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Balsam Fir
Abies balsamea (L.) Miller
Description:
First described in 1768, balsam fir is a medium-sized tree
generally reaching 40-60 feet in height and 1-1 1/2 feet in diameter. It
exhibits a relatively dense, dark-green, pyramidal crown with a slender
spire-like tip. The scientific name "balsamea" is an ancient word for the
balsam tree, so named because of the many resinous blisters found in the bark.
Balsam fir and Fraser fir have many similar characteristics, although
geographic ranges of the two species do not overlap.
On lower branches needles generally occur as two-ranked (two
rows along sides of the branch), 3/4 - 1 1/2 inches long, spreading and not
crowded. On older branches, the needles tend to be shorter and curved upward so
as to cover the upper sides of the twigs. Individual needles are somewhat flat
and may be blunt or notched at the end. Needles have a broad circular base and
are usually dark green on the upper surface, lighter on the lower surface. Two
silvery bands of stomata (pores) are found on the lower surface.
Balsam fir has both male and female flowers (or strobili) on
the same tree. Flowers are receptive in late May to early June. The species is
wind pollinated, and cones mature in a single season. At maturity, cones are 2
to 3 1/2 inches long with bracts shorter than scales. The presence of these
short cone bracts is a distinguishing feature when balsam fir is compared
Fraser fir. Upon ripening in September to November, cones fall apart leaving an
erect central core.
Balsam fir bark is thin, ash-gray, and smooth except for
numerous blisters on young trees. These blisters contain a sticky, fragrant,
liquid resin. Thus, the species has been sometimes referred to as "blister
pine". Upon maturity, bark may become up to 1/2 inch thick, red-brown and
broken into thin scales.
The species thrives in cooler climates and demands abundant
soil moisture and a humid atmosphere. It is generally found in the Canadian and
Hudsonian zones from sea level to about 5,000 feet in elevation. Growth is best
on well-drained, sandy loam soils that are somewhat acid. The species is
tolerant of shade and may reach 150-200 years of age. Pure stands may be found
in swamps, but balsam fir often occurs with white spruce, black spruce and
aspen on upland sites.
Chief enemies are the spruce budworm and balsam woolly
adelgid (formerly called an aphid), heart-rot fungi, and fire. A shallow root
system also renders the trees vulnerable to high winds and heavy spring snow
storms.
As a Christmas tree, balsam fir has several desirable
properties. It has a dark-green appearance, long-lasting needles, and
attractive form. It also retains its pleasing fragrance. Nine to ten years in
the field are required to produce a 6-7 foot tree.
Range:
Abies balsamea occurs naturally from northern
Alberta to Labrador, southward to Pennsylvania. This geographical distribution
is larger than for any other North American fir species. A variety of balsam
fir, phanerolepis, occurs as far south as West Virginia and Virginia
(38 degrees north latitude). This variety is best described as an intermediate
form between balsam fir and Fraser fir although classified with balsam fir.
Propagation:
Most propagation is by seeds, although natural layering may
occur from lower branches in contact with moist soil. A few selected cultivated
forms are commercially propagated by cuttings, and grafting has also been used
for special purposes. Propagation via tissue culture has been attempted but not
on a large scale.
Uses:
The wood is soft and brittle and has been used primarily for
pulpwood. The wood is also used for light frame construction, interior knotty
paneling, and crates. Wood resin in the bark blisters is the source of Canada
balsam used for making of microscope slides. Resin was sold in stores as a
confection prior to the advent of chewing gum, and resinous fir knots were once
used as torches. A balm of balsam fir resin was used in Civil War as an
external application to the injuries of combat. Balsam fir boughs are often
used for stuffing "pine pillows", with the aromatic foliage serving as a
deodorant.
Moose and whitetail deer browse the foliage, while
chickadees, nutcrackers, squirrels and porcupines eat the seeds. The spruce
grouse uses fir forests for cover and obtains food from the needles.
Prepared by Dr. Craig R. McKinley,
North Carolina State University |